Hey guys. I had a Hardtopguy clutch package installed ~5 years ago. Had the ACT pressure plate and lightened flywheel.

After this season of launching on R-comps for autocross, the clutch is slipping. It doesn't hold full running 1-2 shifts. I philosophically agree with the clutch taking some of the hit rather than the full drivetrain shock.

Was looking to replace the clutch package with another Hardtopguy package. Question: Do I need another lightened flywheel? Or just a resurfacing? Or is that something I won't know until the tranny is dropped?

 

something you won't know till tranny is dropped....If money is not an issue then go with the new one....my philosophy is that you don
t want to take it apart again if something is wrong with the flywheel

 

If the FW is not gouged you can just sand it with #100 sandpaper... or take it to a machine shop for a light finishing but don't plan to take much off it.

 

Thanks guys! In thinking about it, I'll probably stick with the HTG package and get another flywheel just in case.

Was thinking about 6-puck disks... but then realized I'd never get it into my trailer!

Maybe in a few years with the InlinePro diff kit, larger trailer, and 4-6 puck kit.....

 

Fidanza flywheels have replaceable contact patches. Seems like a pretty solid investment to me if your gonna change the clutch semi-frequently.

 

As long as their are no fractures the flywheel will be fine. Just like "cdelena" said hit it with sand paper (cheap route) or spend the $30 bucks to have it turned at a machine shop. I wouldn't replace it unless it is necessary or if money is just burning a whole in your pocket.

 

Fidanza flywheels are infamous for warping. Aluminum is not the appropriate material for a flywheel - especially in a high HP situation - regardless of what they use for the friction material.
The issue is strength of the material under high temps, and billet aluminum becomes extremely weak under the temps seen by a flywheel. Additionally, aluminum micro fractures every time it's stresses.

I would never use sandpaper on a flywheel or brake rotor. That kind of back yard maintenance is a waste of time and will almost guarantee you'll have to pull the trans again to properly attend to the flywheel.
The ACT FW may need to be replaced if it's as thin as the Toda. I would call ACT to find out the service limit of the FW.

Additionally, I spoke with Larry at Endyne last week and he stated they don't run the ACT PP due to the higher clamping force and the design of the thrust bearings in the F20/F22. They use Carbonetics dual disc clutches, which I believe come with a FW. I'll be going that route when I change mine out next. I don't know where to find one yet (I'll be talking with Larry this week again), but I'll post the info when I get it.
I'm currently running the ACT PP, OEM disc, and the Comptech FW. The Comptech FW has enough meat that it can be resurfaced 2-3 times.

 

slipstream444 Posted on Aug 4 2008, 01:59 PM
Do you mean that disengaging the clutch with the ACT PP produces "crank walk"?

 

I know I kind of flamed a Supra guy for suggesting this possibility a few months ago - but Larry stated that was one of their concerns based on how the OEM thrust bearings were oiled.
So firstly: Sorry Supra guy I flamed (but don't remember your screen name). I was wrong and your concern was right on the mark. I'll try not to be such a d!ck in the future. I do however believe in admitting when you're wrong - and I was wrong.

Larry stated you can reduce some of the wear problems associated with the higher clamping force PP by bypassing the startup interlock in the clutch pedal and to not sit at a light with the clutch pedal pushed in. I've always done the second part, and I'm working on a momentary switch to bypass the clutch interlock for startup to help reduce wear.

They specifically address this at Endyne in some of the mods they do, but still specifically run the dual plate clutch to avoid having to run a high clamping force pressure plate.

For note, Endyne currently runs a dragster powered by a 2.2 stroked F20. It's normally aspirated but produces almost unthinkable HP numbers on race gas. You'd have to call Endyne to learn more.

 

slipstream444 Posted on Aug 4 2008, 10:02 PM
I've Googled the Carbonetics dual disk for a bit and found some info.
The high price is one thing
They also mentioned a 1300kg and even 1500kg pressure plates used in a dual or tripple Carbonetics clutch.

Does anyone have any idea how the ACT would be rated?
Its obvious its higher than stock, but how much?

One would think, with the pull-to-release pressure plate in the F20/F22, that the thrust bearings are designed to deal force coming in a certain direction.
And.. wouldn't the trans inputshaft help in keeping the crank in place (a bit)?
The trans input shaft sits in the FW's pilot bearing, so the crankshaft does (IMO) get some support from the input shaft.
The input shaft has thrust bearings as well.

Bearing #1 and #2 are angular contact ball bearings, designed to take axial and radial force.